/*

   Derby - Class org.apache.derby.client.am.ClobWriter

   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

*/

package org.apache.derby.client.am;

import org.apache.derby.shared.common.reference.SQLState;


public class ClobWriter extends java.io.Writer {
    private Clob clob_;
    private long offset_;

    public ClobWriter() {
    }

    public ClobWriter(Clob clob, long offset) throws SqlException {
        clob_ = clob;
        offset_ = offset;

        if (offset_ - 1 > clob_.sqlLength()) {
            throw new SqlException(clob_.agent_.logWriter_, 
                new ClientMessageId(SQLState.BLOB_INVALID_OFFSET),
                new Long(offset));
        }
    }

    public void write(int c) {
        StringBuffer sb = new StringBuffer(clob_.string_.substring(0, (int) offset_ - 1));
        sb.append((char)c);
        updateClob(sb);
    }

    public void write(char cbuf[], int off, int len) {
        if ((off < 0) || (off > cbuf.length) || (len < 0) ||
                ((off + len) > cbuf.length) || ((off + len) < 0)) {
            throw new IndexOutOfBoundsException();
        } else if (len == 0) {
            return;
        }
        StringBuffer sb = new StringBuffer(clob_.string_.substring(0, (int) offset_ - 1));
        sb.append(cbuf, off, len);
        updateClob(sb);
    }


    public void write(String str) {
        StringBuffer sb = new StringBuffer(clob_.string_.substring(0, (int) offset_ - 1));
        sb.append(str);
        updateClob(sb);
    }


    public void write(String str, int off, int len) {
        StringBuffer sb = new StringBuffer(clob_.string_.substring(0, (int) offset_ - 1));
        sb.append(str.substring(off, off + len));
        updateClob(sb);
    }

    public void flush() {
    }

    public void close() throws java.io.IOException {
    }
    
    private void updateClob(StringBuffer sb) 
    {
        clob_.string_ = sb.toString();
        clob_.asciiStream_ = new java.io.StringBufferInputStream(clob_.string_);
        clob_.unicodeStream_ 
            = new java.io.StringBufferInputStream(clob_.string_);
        clob_.characterStream_ = new java.io.StringReader(clob_.string_);
        clob_.setSqlLength(clob_.string_.length());
        offset_ = clob_.string_.length() + 1;
    }
}

